3-point wheelchair passenger securement system

ABSTRACT

The embodiments described and claimed herein are improved wheelchair passenger securement systems and stations. In particular, one embodiment described and claimed herein is a drop-in system comprising a barrier module and a wall-side module, which incorporate three separate restraint devices which are configured to secure a wheelchair at three separate attachment points. The system can optionally include a moveable excursion barrier or a pull-mechanism to pre-tension at least one of the restraint devices the wheelchair securements. In a simpler embodiment, three restraint devices, such as retractors, are provided for attachment to the vehicle surfaces or structures in, for example, a generally right-triangular configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending U.S. application Ser. No. 11/847,435, entitled BARRIER WITH INTEGRATED WHEELCHAIR RESTRAINTS, filed Aug. 30, 2007, which is a continuation-in-part of International Application No. PCT/US2006/030085, entitled RESTRAINT SYSTEM, which was and filed on Aug. 2, 2006, and which claims priority to Provisional U.S. Application Ser. No. 60/705,452, entitled RESTRAINT SYSTEM and filed on Aug. 5, 2005. U.S. application Ser. No. 11/847,435 is also a continuation-in-part of U.S. application Ser. No. 11/252,326, entitled RESTRAINT SYSTEM and filed on Oct. 17, 2005 now U.S. Pat. No. 7,452,170, which claims priority to Provisional U.S. Application Ser. No. 60/618,572, entitled AUTOMATIC BELT RETRACTOR RELEASE SYSTEM and filed on Oct. 15, 2004.

This application also claims priority to provisional patent application Ser. No. 61/102,853, entitled 3-POINT WHEELCHAIR PASSENGER SECUREMENT SYSTEM, filed Oct. 5, 2008.

U.S. application Ser. No. 11/847,435, International Application No. PCT/US2006/030085, U.S. application Ser. No. 11/252,326 and Provisional U.S. Application Ser. Nos. 61/102,853, 60/618,572 and 60/705,452 are hereby incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable.

BACKGROUND OF THE INVENTIONS

1. Technical Field

The embodiments described and claimed herein relate generally to wheelchair passenger securement methods, systems, and devices for vehicles. More specifically, at least some of the embodiments described herein relate to a method, system, or device for securing a wheelchair passenger in a vehicle (train, bus, van, plane, etc.) using 3 points of attachment for securing the wheelchair.

2. Background Art

The Americans with Disabilities Act (ADA) mandates that all public transit service providers must accommodate persons with disabilities, including those who must use a wheelchair as their seat in the transport vehicle. ADA also mandates that, for the safety of the wheelchair user and near-by passengers, the wheelchair must be secured so that it will not move more than 2″ in any direction during normal vehicle operation. In addition, restraints must be attached to the wheelchair—historically two in front and two in the rear—that are sufficiently strong to keep it secured in the event of a crash event.

Current systems on the market generally use a four-point system where two restraints are used to secure the front of the wheelchair and two are used to secure the rear of the wheelchair (one on each “corner” of the wheelchair). In that respect, the current systems utilize four attachment points on the vehicle, four attachment points on the wheelchair, and four restraints extending between each respective vehicle attachment point and wheelchair attachment point. The prior art four-point systems are considered by many to be relatively cumbersome and time-consuming to secure, especially if the system is used on a public transit vehicle where dwell times are critical.

The prior art four-point systems suffer from numerous problems or short-comings. For example, the four-point systems utilize two restraint devices for securing the front of the wheelchair, one on the wall-side of the wheelchair and one on the aisle-side of the wheelchair. The use of the additional aisle-side restraint increases the cost of installation (more components and labor), poses a significant obstacle and tripping hazard for wheelchairs and other passengers, and requires more time to secure the chair (increasing vehicle dwell time and the potential for driver injuries while attempting to secure the device). Some have attempted to solve this problem by mounting the aisle-side restraint device to a retractable arm, such as the one disclosed in U.S. Pat. No. 5,888,038, but such a system adds unnecessary expense and still poses a potential tripping hazard.

Others have attempted to vary from the traditional four-point systems with limited success. See, for example, the systems described in U.S. Pat. Nos. 4,060,271; 4,257,644; 4,427,210; 4,492,403; 4,688,843; 4,265,478; 5,026,225; and 6,113,325. One of the attempted solutions utilizes three attachment points on the vehicle. For example, the system disclosed in U.S. Pat. No. 6,113,325 (“the '325 patent”) utilizes three vehicle attachment points or restraint devices (two in the front, one in the rear). However, this system still suffers from the same problems as the traditional four-point system since it also requires the use of a coupling, or some other device, such as a “Y” belt (see reference number 48 in U.S. Pat. No. 6,113,325). Although the coupling is only secured at one end to the single rear restraint device, the coupling is configured to secure the rear of the wheelchair at two wheelchair attachment points. In such systems, there are still effectively four attachment points to the wheelchair. Therefore, such systems are still relatively cumbersome and time-consuming to use. Plus, these systems are inherently weaker than the traditional four-point systems (four vehicle attachment points/four wheelchair attachment points) since they utilize only one restraint device to secure the rear of the wheelchair, where more strength is required to sufficiently restrain the wheelchair during emergency braking events. Also, if the coupling or “Y” belt is not permanently attached, there is the potential to lose the component, rendering the system useless. Further, the vehicle operator must still attach four restraints to the wheelchair as in conventional systems, as well as connect the additional coupling to the rear restraint device. In fact, it is believed that such a configuration may actually increase dwell time and potential for driver injury as compared to traditional four-point systems. Even further, the configuration of these prior art systems are quite complex, which increases the opportunity to use it improperly. It should not be forgotten that driver error is one of the most predominant causes of wheelchair tip-overs in the industry.

U.S. Pat. No. 4,257,644 (“the '644 patent”) also discloses a system utilizing three vehicle attachment points. However, this prior art system utilizes manually operable restraints and coffers, or covered floor pockets, that are bulky, difficult to use, can pose a significant tripping hazard, and require an extra installation as compared to the embodiments described herein. Like the prior art system of the '325 patent, the system disclosed in the '644 patent also only uses a single vehicle attachment point to secure the rear of the wheelchair and is therefore inherently weak. As discussed above, in typical wheelchair securement systems, where the wheelchair passenger is forward facing in the vehicle, more strength is required to secure the rear of the wheelchair, as opposed to the front, to withstand emergency braking events.

BRIEF SUMMARY OF THE INVENTIONS

The embodiments described and claimed herein solve at least some of the problems of the prior art wheelchair restraint systems. In simple terms, the embodiments described and claimed herein utilize three vehicle attachment points and three wheelchair attachment points to effectively secure a wheelchair. Instead of using a fourth wheelchair attachment point like the prior art, the present system may also use a fourth contact or touch point between the wheelchair and a side barrier. The side barrier may be a part of the vehicle itself (such as a side-wall) or could be a separate structure that is rigidly or movably fixed to the vehicle.

In one particular embodiment described and claimed herein, two of the vehicle attachment points and two of the wheelchair attachment points are provided at the rear of the wheelchair, where the most strength is needed for forward facing applications. It has been found that front restraints in most instances mainly come into play on rebound and primarily find use to prevent the front of the wheelchair from swinging out into the aisle. Therefore, only having one vehicle attachment point and one wheelchair attachment point at the front of the wheelchair is sufficient.

The configurations described and claimed herein are simpler to use than the prior art systems since they utilize fewer points of attachment to the vehicle and wheelchair. For the present systems, the opportunity for the driver to improperly secure the wheelchair and to suffer injury is reduced, since there is one and sometimes two less devices to bend down and attach and/or activate. Further, the potential tripping hazard for other passengers and potential liability for vehicle operators is reduced. Even further, utilization of the presently described configurations reduces the amount of installation time required and the maintenance needed for the vehicle's owner.

In one embodiment, a drop-in system comprising a barrier module and a side-wall module is provided. The system is configured for forward-facing securement of a wheelchair (relative to the direction of travel of the vehicle), where the back of the wheelchair is adjacent the barrier module and the side-wall module is adjacent the wall of the vehicle. The barrier module is provided with two tie-down (or securement or restraint) devices for securing the wheelchair from two points, such as the two rear corners of the wheelchair. The side-wall module is provided with a single tie-down device, which is spaced a distance forward from the barrier module, for securing the wheelchair at a single point, such as the front wall-side corner of the wheelchair.

In another embodiment, a similar drop-in system is provided, except that the embodiment includes a movable side barrier, which has a retracted position towards a wall of the vehicle, and an extended position in which the side barrier contacts and exerts a force onto the wheelchair (in a direction away from the wall) to induce pretension in the previously-attached tie-down devices.

In yet another embodiment, a similar drop-in system is provided, except that the side barrier of the third embodiment is fixed, rather than movable.

In yet another embodiment, a similar drop-in system is provided, except that the embodiment includes a pull-mechanism that exerts a force on the single tie-down device (for example, in a direction towards the wall), whereby urging the wheelchair towards the wall (or side barrier) and inducing pre-tension into the tie-down device. The pull-mechanism may be a part of the side barrier or could be a separate structure that is rigidly or movably fixed to the vehicle

In yet another embodiment, a more simple system is provided which includes three tie-down devices arranged in a generally right-triangular configuration, two at the rear of the wheelchair and one at the front of the wheelchair. The tie-down devices can be mounted to any structure of the vehicle, such as the floor or wall.

In yet another embodiment, a single front tie down is provided in combination with a retractable anchor, onto which two rear tie-down devices are attached. In one instance, the retractable anchor includes a housing, which is attached to some portion of the vehicle, such as the floor. The retractable anchor also includes an extendable member, or arm, which is configured to telescope into the housing. The arm is configured to retract into the housing to eliminate a potential tripping hazard for non-wheelchair passengers and to eliminate an obstacle for wheelchair passengers. One of the two tie-down devices would be connected to the housing, and the other to the arm.

Other embodiments, which include some combination of the features discussed above and below and other features which are known in the art, are contemplated as falling within the claims even if such embodiments are not specifically identified and discussed herein.

BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWINGS

These and other features, aspects, objects, and advantages of the embodiments described and claimed herein will become better understood upon consideration of the following detailed description, appended claims, and accompanying drawings where:

FIG. 1 is a perspective view illustrating a first embodiment of a three-point wheelchair securement system, which includes a barrier module and a side-wall module;

FIG. 2 is a front view of the barrier module with portions of the front panel removed;

FIG. 3 is a perspective view illustrating a second embodiment of a three-point wheelchair securement system, which includes a barrier module, a side-wall module, and a pull mechanism, with a properly secured wheelchair passenger;

FIG. 4 is a second perspective view of the second embodiment of the three-point wheelchair securement system, with the wheelchair passenger shown transparent;

FIG. 5 is a perspective view of the pull mechanism for the second embodiment;

FIG. 6 is a perspective view of a third embodiment of a three-point wheelchair securement system, which includes a movable lateral barrier;

FIG. 7 is a perspective view of a fourth embodiment of a three-point wheelchair securement system, which includes three wall or floor-mounted retractors;

FIG. 8 is a perspective view of a fifth embodiment of the three-point wheelchair securement system, which includes a telescoping arm and a wall or floor-mounted retractor;

FIG. 9 is a perspective view illustrating a sixth embodiment of the three-point wheelchair securement system, which includes a barrier module, a side-wall module, and a tensioning mechanism;

FIG. 10 is front view of the sixth embodiment of the barrier module with portions of the front panel removed;

FIG. 11 is an exploded view of the tensioning mechanism of the sixth embodiment;

FIG. 12 is an exploded view of the handle actuator for the tensioning mechanism of the sixth embodiment;

FIG. 13 is a first perspective view of the tensioning mechanism with certain panels removed for purposes of clarity;

FIG. 14 is a second perspective view of the tensioning mechanism with certain panels removed for purposes of clarity; and,

FIG. 15 is a cross sectional view of the tensioning mechanism.

It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the embodiments described and claimed herein or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the inventions described herein are not necessarily limited to the particular embodiments illustrated. Indeed, it is expected that persons of ordinary skill in the art may devise a number of alternative configurations that are similar and equivalent to the embodiments shown and described herein without departing from the spirit and scope of the claims.

Like reference numerals will be used to refer to like or similar parts from Figure to Figure in the following detailed description of the drawings.

DETAILED DESCRIPTION OF THE INVENTIONS

Referring first to FIGS. 1 and 2, a first embodiment of a three-point wheelchair securement system (or station) 10 is shown for securing a wheelchair and its occupant in a vehicle, such as a bus, van, train, aircraft, boat, or the like. The first embodiment of the wheelchair securement system 10 includes a barrier module 20 and a side-wall module 30. With certain exceptions discussed herein, the barrier and side wall modules 20, 30 of the first embodiment are substantially similar to those described in co-pending U.S. patent application Ser. No. 11/847,435, which is incorporated herein in its entirety.

In the first embodiment, the wheelchair securement system 10 is best characterized as a drop-in system for a vehicle which is fully-equipped to secure a wheelchair and its passenger in a forward facing orientation (i.e., with respect to the direction of travel of the vehicle). In this orientation, the barrier module 20 is forward-facing (i.e., positioned rearward of the side-wall module 30 in the vehicle) and secures the wheelchair at two attachment points at the rear of the wheelchair. Although shown in a configuration suitable for installation adjacent a right side wall of a vehicle, the system 10 could be configured as a mirror image of the shown configuration for installation adjacent a left side wall of the vehicle. The side-wall module 30 is positioned adjacent to a wall of the vehicle and secures the wheelchair at a single attachment point at the front of the wheelchair. The barrier module 20 and side-wall module 30, through the use of three points of attachment to the wheelchair, work in conjunction to adequately secure the wheelchair in compliance with the ADA and to prevent significant movement, twisting, or tipping of the wheelchair.

To facilitate simple installation, the shown system 10 is intended to be substantially assembled for a vehicle manufacturer (or retrofitter) and needs only to be mounted or bolted into place without any further significant installation. To achieve this end in a cost-effective manner, the barrier module 20 and side-wall module 30 are provided or shipped as separate units, which are connected together by the installer. However, it is contemplated that alternative embodiments could comprise pre-integrated barrier and side-wall modules or barrier and side-wall modules which are not configured for interconnection.

The first embodiment of the wheelchair securement system 10 includes a side-wall arrangement with seats to make most efficient use of vehicle space. In that respect, the area designated for the wheelchair passenger system 10 can be used for other passengers, sitting and/or standing, when it is not needed for a wheelchair passenger. The side-wall module 30 of the first embodiment incorporates a fold-up seat 32, so that the seat 32 can be positioned out of the way when a wheelchair passenger boards the vehicle. It is, however, contemplated that other seating arrangements could be used, such as forward facing seating. For example, the barrier module 20 could be provided with a similar stowable seat, which can be moved out of the way when the wheelchair securement system 10 is needed.

The wheelchair securement system 10 includes three securement (or tie-down) assemblies 40 a, 40 b, 40 c which work in conjunction to adequately secure a wheelchair in compliance with the ADA. In the first embodiment, each of the three securement assemblies 40 a, 40 b, 40 c comprises a retractor 42 a, 42 b, 42 c. Each retractor 42 a, 42 b, 42 c includes several feet of webbing (or strap) 44 a, 44 b, 44 c, at a terminal end of which is provided a wheelchair engaging member 46 a, 46 b, 46 c which could be any type of fastener. The shown wheelchair engaging member or fastener is an anchor (or S-hook or J-hook) which can be easily attached to and easily removed from any portion of a wheelchair, such as a structural member. Retractors suitable for use in this application include Q'Straint's QRT Series retractors (see www.qstraint.com). As an alternative to the retractors shown herein, manually-adjustable straps can be used, such as Q'Straint's Q-5000 and M-series belt systems.

The retractors 42 a, 42 b, as shown, are mounted internal to the barrier module 20. The only portion of the securement assemblies 40 a, 40 b that protrude from the barrier modules 20 are the restraint straps 44 a, 44 b, and the wheelchair engagement members 46 a, 46 b. The retractor 42 c, as shown, is mounted to the leg of the side-wall module 30, underneath the fold-up seat 32. This configuration substantially reduces the potential tripping hazard for passengers, as compared to prior art systems which include exposed retractors.

While the depictions of the first embodiment show the retractors 42 a, 42 b mounted internal to the barrier module 20, it is contemplated that other embodiments could include retractors mounted external to the barrier module 20. Moreover, while the retractor 42 c is shown mounted to the leg of side-wall module 30, it is contemplated that the retractor 42 c could be mounted to any other portion of the module 30 or to any other component of the vehicle, such as the wall or floor. Indeed, as shown in the figures and described in more detail below, the more simple embodiments of the claimed securement systems may not include a barrier or side-wall module 20, 30 at all. Such simple embodiments could consist of three securement assemblies which are mounted in a generally triangular pattern in the vehicle. The securement assemblies can be fastened to any surface or structure of the vehicle, including the floor and walls.

While the retractors 42 a, 42 b, 42 c could theoretically be mounted directly to a floor surface of the vehicle, with the claims covering such a configuration, it has been found that better performance can be obtained by spacing the retractors 42 a, 42 b, 42 c a distance from the floor, a configuration espoused by the first embodiment of the wheelchair securement system 10. However, the retractors 42 a, 42 b, 42 c should be spaced a slight distance below the wheelchair structure to which the wheelchair engaging members 46 a, 46 b, 46 c will be attached. In other words, it is preferable that the restraint strap 44 a, 44 b, 44 c be slightly angled upwards towards the wheelchair so that the securement assembly 40 a, 40 b, 40 c can exert a downward force on the wheelchair.

The barrier module 20 of the first embodiment also includes a remote control device with a release latch (or paddle handle) 22 for releasing one or more of the securement assemblies 40 a, 40 b, 40 c. For example, the embodiments could include any of the systems described in U.S. provisional patent application Ser. Nos. 60/705,452, U.S. provisional patent application No. 60/618,572, U.S. patent application Ser. No. 11/252,326, and/or PCT patent application no. PCT/US06/30085, which are all incorporated in their entirety herein by reference.

The first embodiment of the wheelchair securement system 10 also includes a side barrier or pad 34. The side barrier 34 can be constructed of any material and can be rigid, soft and/or resilient. For example, the side barrier 34 could comprise high density polyurethane foam similar to car head rests, and could be covered with fabric. Alternatively, a metal, plastic, or rubberized structure could be used.

The side barrier 34 can serve one or more of many different functions. For example, as shown, the barrier serves at least two purposes. First, the barrier 34 provides spacing between the wheelchair and the vehicle wall (and/or the side-wall module 30). The spacing between the wheelchair and the wall/side-wall module 30 that is provided by the side barrier 34 serves to prevent injury to the wheelchair passenger in an accident, should an appendage find its way therebetween. Second, the barrier 34 resists lateral and/or rotative movement of the wheelchair towards the vehicle wall. Ideally, although not necessarily, the wheelchair will be in close proximity or will actually touch the side barrier 34 when properly secured.

In the shown embodiment, it is contemplated that the side barrier 34 would have resilient properties, wherein it would have some give, but still provide firm support for the wheelchair. In an alternative embodiment, the side barrier 34 could be biased outward using, for example, a spring that pushes the side barrier 34 outward. When the front restraint 40 c was hooked up and would pull the chair in, the springs would provide an opposing force to stabilize the chair. As discussed below at least in the context of the second embodiment, the side barrier 34 could also be mechanized or inflatable, wherein it is movable to positively contact the wheelchair and induce pre-tension into the securement assemblies 40 a, 40 b, 40 c.

With reference now to FIGS. 3-4, a second embodiment of a wheelchair securement system 110 is shown. Like the first embodiment, the second embodiment includes a barrier module 120 and a side-wall module 130 that are substantially similar to those described in co-pending U.S. patent application Ser. No. 11/847,435. In addition, the second embodiment of the wheelchair securement system 110 is intended to be a drop-in system and, through the use of three points of attachment to the wheelchair, work in conjunction to adequately secure the wheelchair in compliance with the ADA and to prevent significant movement, twisting, or tipping of the wheelchair.

More specifically, the wheelchair securement system 110 includes three securement (or tie-down) assemblies 140 a, 140 b, 140 c which work in conjunction to adequately secure a wheelchair in compliance with the ADA. Each of the three securement assemblies 140 a, 140 b, 140 c comprises a retractor 142 c, although two of the retractors are mounted internal to the barrier modules in a similar manner as in the first embodiment, and are therefore not shown. Each retractor 142 c includes several feet of webbing (or strap) 144 a, 144 b, 144 c, at a terminal end of which is provided a wheelchair engaging member 146 a, 146 b, 146 c which could be any type of fastener.

The second embodiment of the wheelchair securement system 110 also includes at least one side barrier or pad 134. The side barrier 134 can be constructed of any material, although as shown the side barrier comprises a rubber material. The second embodiment includes a front restraint mechanism 160, disposed within housing 162, that is adapted to pull the wheelchair into contact with the side barrier through use of the strap guide 164. The retractor 142 c, as shown, is mounted to the housing 162 for the front restraint mechanism 160, positioned slightly forward of the strap guide 164. In this configuration, the strap 144 c extends from the retractor 142 c, through the strap guide 164, and to the wheelchair, where the wheelchair engaging member 146 c is attached to the wheelchair. Manipulation of a handle 166 for the mechanism 160 causes the strap guide 164 to retract into the housing 162, thereby drawing up any slack in the strap 164 c and pulling the wheelchair flush up against the side barrier 134. In this configuration, the wheelchair is most secure since tension is introduced into the restraints 140 a, 140 b, 140 c and the contact between the barrier 134 and the wheelchair will limit lateral movement towards the wall, both during normal and emergency driving events.

As with the first embodiment, the second embodiment of the barrier module 120 includes a remote control device with a release latch (or paddle handle) 122 for releasing one or more of the securement assemblies 140 a, 140 b, 140 c, such as any one of the systems described in U.S. provisional patent application Ser. Nos. 60/705,452, U.S. provisional patent application No. 60/618,572, U.S. patent application Ser. No. 11/252,326, and/or PCT patent application no. PCT/US06/30085.

Referring now primarily to FIG. 4, the second embodiment of the wheelchair securement station 110 is shown with a wheelchair properly secured therein, although the wheelchair has been made transparent for purposes of clarity. As previously described, the wheelchair is forward facing in the vehicle. With this orientation in mind, one can envision the wheelchair as having four quadrants 152 a, 152 b, 152 c, 152 d, which are defined by the longitudinal axis 154 and lateral axis 156 of the wheelchair. The securement assemblies 140 a, 140 b, 140 c attach to the wheelchair at three points, one point within three of the four quadrants 152 a, 152 b, 152 c, 152 d of the wheelchair. The first two attachment points are at the rear of the wheelchair, i.e., the engaging member 146 a of the securement assembly 140 a engages with the wheelchair in the rear right-side quadrant 152 a (which in this particular case is also the rear wall-side quadrant 152 a) and the engaging member 146 b of the securement assembly 140 b engages with the wheelchair in the rear left-side quadrant 152 b (which in this particular case is also the rear aisle-side quadrant 152 b). The third attachment point is at the front of the wheelchair. As shown, the engaging member 146 c of the securement assembly 140 c engages with the wheelchair in the front right-side quadrant 152 c (which in this particular case is also the front wall-side quadrant 152 c), although it is contemplated that the front left-side quadrant 152 d (which in this particular case is also the front aisle-side quadrant 152 d), or the dividing line therebetween, could be engaged in the alternative. However, it is believed that greater tip resistance can be achieved by locating the third attachment point as near as possible to the front-right corner of the wheelchair when the wall is adjacent to the right side of the wheelchair. Likewise, when the wall (and the associated side barrier 134) is adjacent to the left side of the wheelchair, it is believed that greater tip resistance can be achieved by locating the third attachment point as near as possible to the front-left corner of the wheelchair.

With reference now to FIG. 5, a first embodiment of the front restraint mechanism 160 is shown with several components omitted for purposes of clarity, including the housing 162 and strap guide 164, which are clearly shown in FIGS. 3-4. The mechanism 160 is a pivot mechanism consisting essentially of a link 170 that pivots about pin 168. At a first, or upper end 172 of the link 170, a handle 166 for operating the mechanism 160 is attached. At a second, or lower end 174 of the link, the strap guide 164 is attached (although not shown). A person of ordinary skill in the art would understand that pulling handle 166 in the direction A causes the second end 174 of the link 170, and thus the strap guide 164, to rotate clockwise about the pin 168. When the handle 166 is pulled in direction A, the strap guide 164 extends into the housing 162 for the mechanism 160 which, as discussed earlier, induces pre-tension into the securement assembly 140 c. Rigidly fixed to the underside of the link 170 is a ratchet 176 that is configured to engage with a pawl 178. The ratchet 176 and pawl 178 are configured to allow clockwise movements of the link 170 and to prevent counter-clockwise movements of the link 170. The mechanism 160 further includes a cable 180, attached at one end 182 to the lower end 167 of the handle 166, and at its opposite end 184 to the pawl 178. A person of ordinary skill in the art would understand that pulling on the handle 166 in direction B would cause the pawl 178 to release from the ratchet 176, thereby allowing the link 170 to be rotated counter-clockwise to release the pre-tension from the securement assembly 140 c.

Turning now to FIG. 6, a third embodiment of a wheelchair securement station 210 is depicted. The third embodiment 210 is quite similar to the first and second embodiments, in that it includes a barrier module 220, a side-wall module 230 with a fold-up seat 232, and three securement (or tie down) assemblies 240 a, 240 b, 240 c, two assemblies 240 a, 240 b (hidden from view) for tying down the rear of the wheelchair and one 240 c for tying down the front of the wheelchair. However, unlike the first embodiment, the securement assemblies 240 a, 240 b are not mounted internal to the barrier module 220, but are instead mounted external to the barrier module 220 on its leg supports.

Also, the securement station 210 includes a side barrier 234 which is disposed on the wall side of the vehicle below the flip-seat 232 and which is movable between a retracted and extended position. In FIG. 4, the side barrier 234 is shown in the extended position where it positively contacts the wheelchair and induces tension into the securement assemblies 240 a, 240 b, 240 c. In a retracted position, the barrier would be positioned generally parallel with the wall of the vehicle. Any means known in the mechanical arts could be used to provide motive force for the side barrier 234, including springs and various types of actuators, including pneumatic cylinders and linear actuators. As an alternative, the movable barrier 234 could comprise an inflatable bellows.

Turning now to FIG. 7, a fourth embodiment of a wheelchair securement station 310 is depicted. The station 310 presents a much more simple configuration than presented by the previously described embodiments and includes three securement assemblies 340 a 1 or 340 a 2, 340 b, 340 c 1 or 340 c 2 aligned in roughly a right-triangle configuration. Like the earlier embodiments, the securement assemblies 340 a 1 or 340 a 2, 340 b, 340 c 1 or 340 c 2 can be retractors. While the earlier embodiments show the retractors attached to various barrier and side-wall modules, the retractors 340 a 1 or 340 a 2, 340 b, 340 c 1 or 340 c 2 of the fourth embodiment can be mounted to any structure in the vehicle; for example, the retractors could be floor or wall mounted. In such configuration, the retractors 340 a 1 or 340 a 2, 340 b, 340 c 1 or 340 c 2 can be directly attached to the wall or floor, or could be attached to the wall or floor using track structures or pocket anchorages. For example, in one installation, Q'Straint's “L” track structure or Slide N' Click pocket anchorages could be used. A bracket of some type could be used to ensure the angle and position of the retractor is optimal.

Although possible, it is not intended that the fourth embodiment 310 will be used in isolation. Indeed, it is contemplated that the retractors 340 a 1 or 340 a 2, 340 b, 340 c 1 or 340 c 2 could be placed below various seating and/or barrier modules. For example, the simple configuration of the fourth embodiment has practical application for retrofitting vehicles having existing seating structures.

With reference now to FIG. 8, a fifth embodiment of the wheelchair securement station 410 is shown. The station 410 is similar to the third embodiment, in that it includes three securement assemblies, which as shown are retractors 440 a, 440 b, 440 c 1 or 440 c 2. The forward-most securement assembly 440 c 1 or 440 c 2 could be attached to any structure in the vehicle, including the floor or wall. Also like the third embodiment, the fifth embodiment 410 has practical application for retrofitting vehicles having existing seating structures.

The fifth embodiment 410 differs from the previous embodiments in that it includes a retractable anchor 420 for securing the rear-side of the wheelchair, such as the one described in co-pending U.S. patent application Ser. No. 11/776,223, which is incorporated in its entirety herein by reference. In the alternative, other retractable anchors could be used, such as the ones shown and described in U.S. Pat. Nos. 5,888,038; 6,113,325; 6,149,359; 6,428,254; 6,575,677; and 6,966,733. As shown, the retractable anchor 420 has two main structural components: the housing 422 and the arm 424. The arm 424 is generally adapted to retract inside of the housing 422 when the anchor 420 is not being used to restrain a wheelchair, in order to increase the available floor space for non-wheelchair passengers. Onto each of the housing 422 and arm 424 is mounted a securement assembly 440 a, 440 b. When the retractable anchor 420 is fully extended, as shown, the securement assembly 340 b is properly positioned for attachment to a wheelchair.

Turning now to FIGS. 9-15, a sixth embodiment of the wheelchair securement station 610 is shown. Like the second embodiment, the sixth embodiment includes a barrier module 620 and a side-wall module 630 that are substantially similar to those described in co-pending U.S. patent application Ser. No. 11/847,435, and is intended to be a drop-in system. Also like the second embodiment, the sixth embodiment of the wheelchair securement system 610 uses three points of attachment to the wheelchair, which work in conjunction with a side barrier 634 and a front restraint mechanism, or tensioner assembly, 160 to adequately secure the wheelchair in compliance with the ADA and to prevent significant movement, twisting, or tipping of the wheelchair.

More specifically, the wheelchair securement system 610 includes three securement (or tie-down) assemblies 640 a, 640 b, 640 c which work in conjunction to adequately secure a wheelchair in compliance with the ADA. As best shown in FIGS. 10 and 11, each of the three securement assemblies 640 a, 640 b, 640 c comprises a retractor 642 a, 642 b, 642 c. Retractors 642 a, 642 b are mounted internal to the barrier module 620, and retractor 642 c is mounted to the side-wall barrier 630 inside of a housing assembly 641. Each retractor 642 a, 642 b, 642 c includes several feet of webbing (or strap) 644 a, 644 b, 644 c, at a terminal end of which is provided a wheelchair engaging member 646 a, 646 b, 646 c which could be any type of fastener. At least the front retractor 642 c includes a locking mechanism and a lever, or actuator, 643 c. The locking mechanism prevents the webbing 644 c from being pulled out of the retractor 642, and depressing the lever 643 c overrides the locking mechanism and allows the webbing 644 c to be extended.

Like the second embodiment, the sixth embodiment of the wheelchair securement system 610 also includes at least one side barrier or pad 634. The side barrier 634 can be constructed of any material, although as shown the side barrier comprises a rubber (or neoprene) material. As shown, the side barrier 634 includes a recessed area 635 adjacent the barrier module 620, and a projected area 636 near the front securement assembly 640 c, to accommodate or conform to the shape of a wheelchair which is wider at the rear and more narrow at the front. However, it is anticipated the side barrier 634 could be flat without the recessed area. The contact/side barrier 634 is preferably positioned adjacent or near a floor of the vehicle, underneath a side seating arrangement, but can be adjusted up or down to accommodate different seating options.

With particular reference now to FIGS. 11-15, the sixth embodiment includes a second embodiment of a front restraint mechanism 660, disposed within housings 662 and 641, that is adapted to pull the wheelchair towards or into contact with the side barrier 634 through use of the strap guide 664. The retractor 642 c, as shown, is mounted to the frame structure 631 for the side-wall module 630, positioned slightly forward of the strap guide 664 and a loop member 663, which is affixed to the frame structure 631. In this configuration, the strap 644 c extends from the retractor 642 c, through the loop member 663, then through the strap guide 664, and finally to the wheelchair, where the wheelchair engaging member 646 c is attached to the wheelchair. The strap guide 664 is interconnected with a handle actuator 666 by means of shaft 668. Shaft 668 is rigidly fixed to both the strap guide 664 and the handle actuator 666, and extends through an aperture 633 through the frame structure 631. With this configuration, it is readily obvious that rotation of the handle actuator 666 about the axis of the shaft 668 causes the strap guide 664 to rotate in a similar direction. More specifically, pulling the handle actuator 666 away from the vehicle wall (i.e., clockwise about axis of shaft 668, in direction C) causes the strap guide 664 to rotate in a direction generally towards the vehicle wall, thereby drawing up any slack in the strap 664 c and pulling the wheelchair adjacent to or flush up against the side barrier 634. In this configuration, the wheelchair is most secure since tension is introduced into the restraints 640 a, 640 b, 640 c and the close positional relationship or contact between the barrier 634 and the wheelchair will limit lateral movement towards the wall, both during normal and emergency driving events.

The mechanism 660 includes components which are configured to engage with the lever 643 c on the front retractor 642 c. Specifically, when the securement system 610 is not being used (i.e., when the handle actuator 666 is positioned generally vertical in engagement with spring lock 667), the mechanism 660 is configured to depress lever 643 c, thereby allowing the strap 644 c to be withdrawn from the retractor 642 c. Lever 643 c is depressed using link 670 which is pivotably attached to the frame assembly. Spring 671 is interconnected between the frame structure 631 and the first, or lower portion, 672 of the link 670 to bias the lower portion 672 of the link 670 away from the lever 643 c. Therefore, in its default state, lever 643 is not depressed. However, the mechanism includes cam member 669 which is rigidly fixed to shaft 668. When the handle actuator 666 is positioned generally vertical (i.e., the unlocked/unrestrained position), the cam member 669 engages with the underside of the second, or upper portion, 674 of the link to force the lower portion 672 of the link towards and into engagement with lever 643 c. See, in particular, the cross section in FIG. 15, which shows cam member 669 forcing link 670 into engagement with lever 643 c. In that respect, when the station is not being use, and the handle actuator 666 is in the unlocked/unrestrained position, the strap 644 c can be readily withdrawn from the retractor 642 c so that the fastener 646 c can be engaged with a wheelchair. One of ordinary skill in the art would recognize that when handle actuator 666 is pulled in direction C (to the locked/restrained position), cam member 669 rotates in the same direction, thereby allowing spring 671 to pull the first portion 672 of link 670 away from engagement with lever 643 c. When this occurs, the locking mechanism of the retractor 642 c is engaged, which prevents further strap 644 c from being withdrawn.

With reference now, in particular, to FIGS. 11, 12, and 14, the mechanism 660 includes a ratchet 676 and pawl 678, which work in conjunction to allow the handle to be pulled clockwise, in direction C, but prevent the handle from moving counterclockwise. More specifically, the ratchet 676 is rigidly affixed to the frame structure 631, and includes a stop 677 to prevent over-rotation of the handle actuator 666 (or can be adjusted to limit the travel of the handle 666), while the pawl 678 is pivotably affixed to a lower end of the handle actuator 666. A spring 679 is provided, which is interconnected between the pawl 678 and the handle actuator 666 and biases a first end 680 of the pawl 678 into engagement with the ratchet 676.

The handle actuator 666 includes a ratchet release mechanism, 690, comprising a handle 692 which is connected to a cam follower 696, via a torsion member 694. The torsion member extends from the handle 692 to the cam follower 696 through the tubular body 684 of the handle actuator 666. The handle is configured to rotate in at least one direction D about the axis of the tubular body 684 to facilitate engagement of pawl 678 with ratchet 676. More specifically, torsion member 694 transmits the torque exerted upon the handle 692 to cam follower 696 whereby rotation of handle 692 causes cam follower 696 to rotate about the axis of the tubular body 684. Cam follower 696 engages with cam surface 683 which is present on a second end 682 of the pawl 678. When handle 682 is rotated counterclockwise, cam follower 696 rides along cam surface 683 and forces the second end 682 of the pawl 678 downward, whereby the first end 680 of the pawl 678 moves upward and out of engagement with the ratchet 676.

As with some of the previous embodiments, the sixth embodiment of the barrier module 620 includes a remote control device with a release latch (or paddle handle) 622 for releasing one or more of the securement assemblies 640 a, 640 b, 640 c, such as any one of the systems described in U.S. provisional patent application Ser. Nos. 60/705,452, U.S. provisional patent application No. 60/618,572, U.S. patent application Ser. No. 11/252,326, and/or PCT patent application no. PCT/US06/30085. In the shown embodiment, paddle handle 622 releases the locking mechanisms of retractors 642 a, 642 b for a predetermined amount of time, which is sufficient for the vehicle operator to engage/release the fasteners 646 a, 646 b with/from the wheelchair.

Proper restraint of a wheelchair in the sixth embodiment of the system 610 can be achieved using the following steps. First, the side seat should be placed and locked in the folded, upward position. Second, the wheelchair is moved into position with the back of the passenger placed adjacent the barrier module 620, and the wheelchair positioned in the center of the area, as close as possible to the side barrier 634 (ideally in contact with the side barrier 634). Third, the paddle handle 622 is pulled, which releases the locking mechanisms of retractors 642 a, 642 b for a predetermined period of time. Fourth, webbing 644 a, 644 b is withdrawn and fasteners 646 a, 646 b are attached to structural members of the wheelchair. Preferably, and as described in more detail above for the second embodiment, fastener 646 a engages with the wheelchair in the rear right-side quadrant 652 a, and the fastener 646 b engages with the wheelchair in the rear left-side quadrant 652 b. Fifth, the vehicle operator should verify that the handle actuator 666 is in its unlocked/unrestrained position, so that the locking mechanism of retractor 642 c is disengaged and webbing 644 c can be withdrawn. As shown, the handle actuator 666 is in its unlocked/unrestrained position when it is generally vertical and held in place by spring lock 667. Then webbing 644 c is withdrawn and fastener 646 c engages with the wheelchair in the front right-side quadrant 152 c (i.e., the quadrant adjacent the wall of the vehicle). Sixth, preferably after the predetermined period of time has elapsed, the handle actuator 666 is pulled in direction C. This action simultaneously causes the locking mechanism of retractor 642 c to engage (and thereby prevent further withdrawal of webbing 646 c) and the strap guide 664 to pull webbing 644 c towards the wall of the vehicle (and thereby remove slack from at least webbing 644 c). Engagement of the ratchet 676 and pawl 678 hold the handle actuator 666 in the locked/restrained position. Finally, once everything is secured and in position, the wheelchair wheel locks are then engaged or power supply is turned off. In its final, restrained position, the wheelchair is positioned very close to or ideally in contact with the side barrier 634.

When the wheelchair passenger decides to disembark the vehicle, the above steps are essentially performed, but in reverse order. First, the handle 692 of the handle actuator 666 is rotated to disengage the pawl 678 from the ratchet 676. This allows the handle actuator 666 to be moved back to its original unlocked/unrestrained position. Once this step is performed, the locking mechanism of retractor 642 c is once again released, which allows the fastener 646 c to be removed from the wheelchair and the webbing 644 c to be drawn back into the retractor 642 c. Second, the paddle handle 622 is once again pulled, which allows fasteners 646 a, 646 b to be removed from engagement with the wheelchair and webbing 644 a, 644 b to be drawn back into the retractors 642 a, 642 b. Finally, the vehicle operator removes the wheelchair wheel locks or turns power supply on for electric wheelchairs and the wheelchair passenger is now free to disembark the vehicle.

Although the inventions described and claimed herein have been described in considerable detail with reference to certain embodiments, one skilled in the art will appreciate that the inventions described and claimed herein can be practiced by other than those embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein. 

We claim:
 1. In a vehicle, a securement system comprising: a first, second, and third restraint for securing a wheelchair; the first restraint for connection between the vehicle and only a first wheelchair attachment point; the second restraint for connection between the vehicle and only a second wheelchair attachment point: the third restraint for connection between the vehicle and only a third wheelchair attachment point; the first and second restraints being connected to the vehicle at a rear side of the wheelchair and third restraint being connected to the vehicle adjacent a first front corner of the wheelchair; and the first and second wheelchair attachment points being generally at a rear portion of the wheelchair and the third wheelchair attachment point being generally at the first front corner of the wheelchair; wherein the wheelchair has four quadrants including a front aisle-side quadrant, a front wall-side quadrant, a rear aisle-side quadrant, and a rear wall-side quadrant; wherein the first wheelchair attachment point is disposed generally within the rear wall-side quadrant, the second wheelchair attachment point is disposed generally within the rear aisle-side quadrant, and the third wheelchair attachment point is disposed generally within the front wall-side quadrant; and, wherein the wheelchair is unrestrained at the front aisle-side quadrant.
 2. The wheelchair securement system of claim 1, further comprising a first module and a second module, wherein the first module is adjacent the rear portion of the wheelchair and holds the first and second restraints and the second module is adjacent a side wall of the vehicle and holds the third restraint.
 3. The wheelchair securement system of claim 2, wherein the first module includes a wheelchair passenger restraint belt.
 4. The wheelchair securement system of claim 2, further comprising a lateral barrier positioned between a side of the wheelchair and the side wall of the vehicle.
 5. The wheelchair securement system of claim 4, further comprising a tensioning mechanism for at least one of the first, second, or third restraint.
 6. The wheelchair securement system of claim 5 wherein the second module holds the tensioning mechanism.
 7. The wheelchair securement system of claim 4, wherein the lateral barrier comprises a resilient material that conforms to a side contour of the wheelchair to resist movement of the wheelchair.
 8. The wheelchair securement system of claim 1, further comprising a lateral barrier, wherein: at least a portion of the lateral barrier is longitudinally positioned between the third restraint, and the first and second restraints; and, the third restraint is laterally positioned between the wheelchair and a side wall of the vehicle whereby the third restraint urges the wheelchair towards the lateral harrier.
 9. The wheelchair securement system of claim 1 further comprising a tensioning mechanism, wherein the tensioning mechanism induces tension into at least one of the first, second, or third restraint.
 10. The wheelchair securement system of claim 9, wherein: the tensioning mechanism is movable at least between a first position and a second position; the tensioning mechanism comprises a moveable restraint guide, the moveable restraint guide engaging a portion of the third restraint and applying a force to the third restraint to increase tension of the third restraint when the tensioning mechanism is moved from the first position to the second position.
 11. The wheelchair securement system of claim 10, wherein: the tensioning mechanism further includes a handle, a pivoting member and an engagement member; the third restraint has a release; the handle and the restraint guide are fixed at opposite ends of the pivoting member whereby the pivoting member defines a pivot axis for the handle and restraint guide; the pivot axis is aligned parallel to the longitudinal axis of the vehicle and is laterally positioned between the third restraint and a wall of the vehicle, whereby the restraint guide pulls the portion of the third restraint toward the wad of the vehicle when the tensioning mechanism is placed in the second position; and, the engagement member engages the release when the tensioning mechanism is placed in the first position.
 12. The wheelchair securement system of claim 11 further comprising a frame, a ratchet, and a pawl, wherein the ratchet and the pawl are interposed between the tensioning mechanism and the frame to allow the tensioning mechanism to freely move from the first position to the second position, but to preclude the tensioning mechanism from freely moving from the second position to the first position.
 13. The wheelchair securement system of claim 1, wherein the first, second and third restraints are retractors and the wheelchair securement system further comprises a restraint control assembly, the restraint control assembly being operatively associated with at least one of the first, second, or third restraints to manipulate the at least one of the first, second, or third restraints between a locked position and a released position, whereby activation of the restraint control assembly places the at least one of the first, second, or third restraints in the released position for a period of time.
 14. The wheelchair securement system of claim 1 further comprising a tensioning mechanism, wherein the tensioning mechanism adds tension into the third restraint.
 15. The wheelchair securement system of claim 1 further comprising a tensioning mechanism, wherein the tensioning mechanism aids in tensioning the third restraint.
 16. In a vehicle, a securement system comprising: a lateral barrier, a tensioning mechanism, and a group of wheelchair restraint retractors for securing a wheelchair, the group of wheelchair restraint retractors consisting of a first retractor, a second retractor, and a third retractor, each having a wheelchair engaging member for releasable attachment to the wheelchair; the first, second and third retractors being positioned in a triangular configuration, the first and second retractors positioned to a rear of the wheelchair and the third retractor positioned to a front of the wheelchair; at least a portion of the lateral barrier being longitudinally positioned between the third retractor, and the first and second retractors, and laterally positioned between the wheelchair and a side wall of the vehicle; and, the tensioning mechanism being a component separate from the third retractor and cooperating with the third retractor to urge the wheelchair into contact with the lateral barrier.
 17. The securement system of claim 16, wherein the tensioning mechanism comprises a pivoting restraint guide, through which the retractable restraint of the third retractor passes, the pivoting restraint guide applying a force to an intermediate portion of the retractable restraint of the third retractor whereby the wheelchair is urged toward contact with the lateral barrier.
 18. In a vehicle, a securement system comprising: a rear-barrier module and side-barrier module for securing a wheelchair; the rear-barrier module positioned adjacent and generally perpendicular to a side wall of the vehicle, the side-barrier module extending transversely to a front side of the rear-barrier module and generally parallel to the side wall of the vehicle, whereby the rear-harrier module and the side-barrier module define a securement area for the wheelchair; the rear-barrier module and the side-barrier module collectively including a group of wheelchair restraints retractors consisting of a first restraint, a second restraint, and a third restraint, the first restraint having a first wheelchair engaging member which is releasably attached to the wheelchair, the second restraint having a second wheelchair engaging member which is releasably attached to the wheelchair, and the third restraint having a third wheelchair engaging member which is releasably attached to the wheelchair; the rear-barrier module holding the first and second restraints, the side-barrier module holding the third restraint; the rear-barrier module including at least one lap restraint assembly and a shoulder restraint assembly which are operable to secure a seated wheelchair occupant in the wheelchair; the rear-barrier module including a restraint control assembly, the restraint control assembly being operatively associated with at least one of the first and second restraints to manipulate at least one of the first and second restraints between a locked position and a released position, whereby activation of the restraint control assembly places at least one of the first and second restraints in the released position for a period of time; the side-barrier module including a lateral barrier and a tensioning mechanism; the lateral barrier extending along a length of the side-barrier module whereby at least a portion of the lateral barrier is positioned between the third retractor, and the first and second restraints, a contact surface of the lateral barrier being laterally positioned between the wheelchair and the third restraint; and, the tensioning mechanism being a component separate from the third restraint and applying a force to a portion of the third restraint whereby the wheelchair is urged toward contact with the lateral barrier.
 19. The securement system of claim 18, wherein the side-barrier module includes a stowable seat positioned above the lateral barrier.
 20. The wheelchair securement system of claim 18 wherein the tensioning mechanism comprising a pivoting restraint guide, through which the retractable restraint of the third retractor passes, the pivoting restraint guide applying the force to the portion of the retractable restraint whereby the wheelchair is urged toward contact with the lateral barrier.
 21. In a vehicle, a wheelchair securement system comprising: a lateral barrier, a tensioning mechanism, a group of wheelchair restraint retractors, and a restraint control assembly; the group of wheelchair restraint retractors consisting of a first retractor, a second retractor, and a third retractor, each having a restraint and a wheelchair engaging member; the first, second and third retractors being positioned in a triangular configuration, the first and second retractors positioned in a rear portion of a wheelchair securement area and the third retractor positioned in a front-corner portion of the wheelchair securement area; at least a portion of the lateral barrier being longitudinally positioned between the third retractor, and the first and second retractors, and being positioned adjacent a side wall of the vehicle; the tensioning mechanism adding tension to the restraint of at least one of the first, second, or third retractor; and, the restraint control assembly being operatively associated with at least one of the first, second, or third retractors to manipulate the at least one of the first, second, or third retractor between a locked position and a released position, whereby activation of the restraint control assembly places the at least one of the first, second, or third retractor in the released position for a period of time.
 22. The wheelchair securement system of claim 21 the tensioning mechanism is external to the third retractor and engages with the restraint of the third retractor to add tension into the restraint of the third retractor.
 23. A method for securing a wheelchair in a vehicle using a wheelchair securement system, the wheelchair securement system including a group of wheelchair restraints consisting of a first restraint, a second restraint, and a third restraint, the wheelchair being disposed between a wall and an aisle of the vehicle, the method comprising the steps of: attaching the first restraint to the wheelchair at a first wheelchair attachment point; attaching the second restraint to the wheelchair at a second wheelchair attachment point; attaching the third restraint to the wheelchair at a third wheelchair attachment point, whereby the first, second, and third wheelchair attachment points are substantially the only points of attachment to the wheelchair for securing the wheelchair in the vehicle.
 24. The method of claim 18 wherein the wheelchair is defined by a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant, the first wheelchair attachment point being disposed generally within the first quadrant, the second wheelchair attachment point being generally disposed within the second quadrant, the third wheelchair attachment point being generally disposed within the third quadrant, the method further comprising the step of leaving the wheelchair unrestrained at the fourth quadrant.
 25. The method of claim 18, wherein the wheelchair securement system includes a tensioning mechanism for the third restraint, the method further comprising the step of engaging the tensioning mechanism to induce pretension in the third restraint.
 26. A method for securing a wheelchair in a wheelchair securement area of a vehicle using a wheelchair securement system, the wheelchair securement system including a group of wheelchair restraint retractors consisting of a first retractor, a second retractor, and a third retractor, the wheelchair securement area being disposed between a wall and an aisle of the vehicle wherein the wheelchair securement area is defined by a front wall-side quadrant, a front aisle-side quadrant, a rear wall-side quadrant, and a rear aisle-side quadrant, the method comprising the steps of: installing the first, second, and third retractors in the vehicle so that the first retractor is disposed generally within the rear wall-side quadrant of the wheelchair securement area, the second retractor is disposed generally within the rear aisle-side quadrant of the wheelchair securement area, and the third retractor is disposed generally within the front wall-side quadrant of the wheelchair securement area; and, providing no means for securing the wheelchair from the front aisle-side quadrant of the wheelchair securement area.
 27. The method of claim 26 wherein the wheelchair securement system also includes a lateral barrier, the method further comprising the step of installing the lateral barrier in the vehicle adjacent the wall of the vehicle.
 28. The method of claim 27 wherein the wheelchair securement system also includes a tensioning mechanism, the method further comprising the step of installing the tensioning mechanism in the vehicle with the tensioning mechanism configured to engage with a restraint of the third retractor. 